title: Ni-catalyzed reductive homocoupling of unactivated alkyl bromides at room temperature and its synthetic application.
abstract: A room-temperature Ni-catalyzed reductive approach to homocoupling of unactivated primary, secondary, and tertiary alkyl bromides is described. The catalytic system can be easily generated from air-stable and cheap materials and demonstrates broad functional group tolerance, thus allowing facile access to useful dimeric triterpene and lignan-like molecules. Moreover, the dimerization of tertiary bromide 6 efficiently establishes sterically hindered vicinal quaternary carbons (C3a and C3a'), which is a key linkage of intriguing bispyrrolo[2,3-b]indoline alkaloids, thereby enabling us to complete the total syntheses of racemic chimonanthine (9) and folicanthine (10). In addition, this dimerization method can be expanded to the highly stereoselective synthesis of bisperhydrofuro[2,3-b]furan (5a) and the dimeric spiroketal 5b, signifying the involvement of possible radical species.
authors.affiliation: State Key Laboratory of Applied Organic Chemistry, Key Laboratory of Nonferrous Metals Chemistry and Resources Utilization of Gansu Province, and College of Chemistry and Chemical Engineering, Lanzhou University , Lanzhou 730000, People's Republic of China.
authors.forename: Yu
authors.initials: Y
authors.lastname: Peng
authors.forename: Long
authors.initials: L
authors.lastname: Luo
authors.forename: Chang-Song
authors.initials: CS
authors.lastname: Yan
authors.forename: Jian-Jian
authors.initials: JJ
authors.lastname: Zhang
authors.forename: Ya-Wen
authors.initials: YW
authors.lastname: Wang
mesh_terms: D001965:Bromides / Q000737:chemistry*; D002384:Catalysis; D019281:Dimerization; D005663:Furans / Q000138:chemical synthesis* / Q000737:chemistry; D006842:Hydrocarbons, Brominated / Q000138:chemical synthesis* / Q000737:chemistry; D007211:Indoles / Q000138:chemical synthesis / Q000737:chemistry; D015394:Molecular Structure; D009532:Nickel / Q000737:chemistry*; D011758:Pyrroles / Q000138:chemical synthesis / Q000737:chemistry; D013237:Stereoisomerism; D013696:Temperature
chemical_list: D001965:Bromides; D005663:Furans; D006842:Hydrocarbons, Brominated; D007211:Indoles; D011758:Pyrroles; C000588746:bisperhydrofuro(2,3-b)furan; C521485:folicanthine; D009532:Nickel; C521484:chimonanthine